package helloworld;

import java.util.HashSet;
import java.util.Iterator;

public class HashSetTest {

    public static void main(String[] args) {
        System.out.println("Collection Example!\n");
        int size;
        
        // Create a collection      
        HashSet<String> collection = new HashSet<String>();
        String str1 = "Yellow", str2 = "White", str3 = "Green", str4 = "Blue";
        Iterator iterator;
        
        
        //Adding data in the collection
        collection.add(str1);
        collection.add(str2);
        collection.add(str3);
        collection.add(str4);
        System.out.print("Collection data: ");
        
        //Create a iterator
        iterator = collection.iterator();
        while (iterator.hasNext()) {
            System.out.print(iterator.next() + " ");
        }
        System.out.println();
        
        // Get size of a collection
        size = collection.size();
        if (collection.isEmpty()) {
            System.out.println("Collection is empty");
        } else {
            System.out.println("Collection size: " + size);
        }
        System.out.println();
        
        // Remove specific data      
        collection.remove(str2);
        System.out.println("After removing [" + str2 + "]\n");
        System.out.print("Now collection data: ");
        iterator = collection.iterator();
        while (iterator.hasNext()) {
            System.out.print(iterator.next() + " ");
        }
        System.out.println();
        size = collection.size();
        System.out.println("Collection size: " + size + "\n");
        
        //Collection empty
        collection.clear();
        size = collection.size();
        if (collection.isEmpty()) {
            System.out.println("Collection is empty");
        } else {
            System.out.println("Collection size: " + size);
        }
    }
}